Lab‐scale testing of operation parameters for algae based treatment of piggery wastewater

Abstract

BACKGROUND Microalgae–bacteria‐based processes are among the most promising low‐cost technologies to treat livestock wastewaters. The current literature reports the need for pretreatment or dilution of piggery wastewater for adequate microalgal growth. The aim of this study is to optimize the potential of microalgal–bacterial communities to treat undiluted and untreated piggery wastewater by investigating the influence of some operational parameters such as phosphorus and CO2 availability and hydraulic retention time on the nitrogen removal efficiency and biomass productivity. RESULTS The microalgal community (dominated by Chlorella spp.) developed quickly and remained quite stable. The rates of biomass production and NH4‐N removal were 55 ± 30 mg TSS L−1 day−1 and 13 ± 3 mg NH4‐N L−1 day−1 respectively. CO2 adjustment had a positive effect on microalgal growth and NH4‐N removal. CONCLUSION Data confirm the ability of the microalgal–bacterial consortium to grow on undiluted and untreated piggery wastewater under semi‐continuous conditions. Synergy between algae and bacteria seems positive since photosynthesis produces the oxygen needed for ammonia oxidation. © 2019 Society of Chemical Industry

Microalgae cultivation for the treatment of anaerobically digested municipal centrate (ADMC) and anaerobically digested abattoir effluent (ADAE)

“…Despite the visible difference in turbidity of the ADMC (109 FAU) and ADAE (43 FAU), similar biomass productivity and growth performance of microalgae recorded in both wastewaters indicates that light only becomes a limiting factor when turbidity is beyond a threshold (Table 1) (Wang et al, 2010). It is interesting to note that the turbidity of the AD effluent used in this study were comparable or lower than that of other raw and pre-treated wastewater that have been successfully used for cultivation of microalgae (Hodaifa et al, 2020;Marazzi et al, 2020). This is a promising outcome as both ADMC and ADAE used in this study were not subjected to any costly pre-treatment steps (i.e.…”

Effect of N:P Ratio on Microalgae/Nitrifying Bacteria Community in Agro-Digestate Treatment

“…In each PCR reaction (total volume 20 μL) 3 μL of DNA was added to a mix solution containing Power SYBR Green PCR Master Mix (Applied Biosystems, USA) and 100 nM of each primer. The PCR cycles were performed on AB 7300 Real-Time PCR System (Life Technologies, Italy) as described in Bellucci et al (2015) and [20], [21]. The 16S rRNA gene copy numbers were then converted to equivalent cell numbers assuming that an average of 4.2 rRNA operon exists in each bacterial cell; whereas the number of AOB was estimated by considering 2 copies of amoA gene in each AOB cell [22], [23].…”

Comparison of the Performance and Microbial Community Structure of Two Outdoor Pilot-Scale Photobioreactors Treating Digestate

“…The reactions were performed on a 7500 Fast Real-Time PCR system (Applied Biosystem, Monza, Italy) equipped with Applied Biosystems 7500/7500 Fast Real-Time PCR Software (7500/7500 Fast software). PCR reactions were performed as described in Marazzi et al, 2019 [34]. Standard DNA were constructed from purified PCR amplicons from pure cultures of Nitrosomonas communis (DSMZ 2843) for bacterial, and Nitrosomonas eutropha (DSMZ 101675) for AOB.…”

“…Complete nitrification could be achieved only in the RWP, while partial nitrification occurred in the PBR. High ammonium oxidation is quite common in microalgae-based technologies treating municipal and agro-zootechnical digestate [34,54,55], especially if phosphorus is readily available [65]. The elevated P concentration in the centrate favored the activity of the AOB [66], which are the main responsible for ammonium oxidation.…”